The three 'bodies' of a buddha. They relate not only to the truth in us, as three aspects of the true nature of mind, but to the truth in everything. Everything we perceive around us is nirmanakaya; its nature, light or energy is sambhogakaya; and its inherent truth, the dharmakaya.

Further Reading

Sogyal Rinpoche, The Tibetan Book of Living and Dying revised and updated edition (HarperSanFrancisco and London: Rider, 2002), pages 346-347.